Build on Harmony Bridge to All Chains

6 min readAug 18, 2021


499Block:Our ama is about to start, let us warmly welcome our guest of the day! @RongjianLan

Rongjian Lan:Hi, 499 Block community, really excited to join this great community and share with you guys our progress on Harmony blockchain.

499Block:So now our ama will officially start. Before that, we ask our speaker @RongjianLan to make a short self-introduction.

Rongjian Lan:Sure, I am Rongjain Lan, the co-founder and CTO of Harmony. I am in charge of the design and implementation of Harmony blockchain core protocol. Would be happy to answer any questions about Harmony.

499Block:That was Impressive experience, great, then let’s start today’s theme of Harmony!

Harmony as a top-notch blockchain ecosystem, can you tell us what Harmony is all about?

Rongjian Lan:Absolutely, Harmony is a high-performance public blockchain that’s based on Proof-of-Stake and sharding technology. Harmony aims to connect all blockchains through trustless bridges, serving as a hub for cross-chain Dapps and cross-chain liquidity pools.

The idea for Harmony was originally created in 2017 when we first experienced the scalability issue of Ethereum on popular Dapps like CryptoKitties.

In 2018, the Harmony design and whitepaper were finished and the Harmony team was formed. Our team consists of engineers from Google, Amazon, Apple, Microsoft etc. and our business team having MBA graduates from Harvard and with many years of experience in crypto space. Btw, our CEO Stephen is a serial entrepreneur who sold his first Startup to Apple Inc.

Harmony was one of the Binance IEO projects in 2019 and was one of the most successful IEO launch in Binance. Right after binance IEO, we launched our mainnet in June 2019 with 4 shards and 600 nodes and became the first launched mainnet blockchain with PoS and sharding.

499Block:It sounds great! This high-performance public chain seems to be a huge advantage of the project, and then comes the second question.

Who are your competitors? Why do you think you can stand out from your competitors?

Rongjian Lan:That’s a good question. There are many aspects to compare Harmony with other competitors. And actually we can compete both as a layer 1 and layer 2 solutions since we have trustless bridge connecting us to Ethereum blockchain.

Compared to other layer 1 solutions, we have top-notch consensus performance and block finality. Our FBFT consensus was a carefully designed consensus protocol which leverages the latest crypto primitives called BLS signatures to achieve an efficient consensus process.

Coupled with efficiency-focused implementation, FBFT consensus allows blocks to be produced and finalized every 2 seconds. For users, the transaction confirmation time is also 2 seconds, which leads to a smooth and nice user experience.

In the meantime, the transaction fee is only around $0.0001 per txn, so it’s very affordable to use Harmony. Besides, our network currently has 4 shards with 1000 validating keys from 120+ unique validators. So it’s fairly decentralized and very secure, there is not a single security incident since the launch of mainnet in 2019 and hundreds of millions of blocks and transactions have been successfully processed so far.

Compared to other layer 2 solutions, we are similarly connected to Ethereum and users can move their assets easily between Ethereum and Harmony.

What’s better in Harmony is that the withdrawal process only takes a few minutes while most layer 2s take a few hours if not a week to fully finish the withdrawal.

Meanwhile, our fast transaction latency of 2 seconds and minimal fee is comparable to those offered in other layer 2 solutions. So Ethereum developers and users can enjoy the same performance and low-cost in Harmony just like other layer 2 solutions such as Rollup and sidechains.

499Block:You said Very clear! Compared to other projects, Harmony’s advantages are very obvious! So the third question.

What is the current progress of Harmony? Can you share it with us?

Rongjian Lan:Sure. Since 2018, we’ve been working continuously on implementing the original design of the protocol. So far, We’ve finished most part of the design, including FBFT consensus with 2 second finality, sharded network with 4 shards, full evm-compatible toolings, cross-shard transactions, EPoS staking mechanism, and VRF onchain randomness etc.

Right now, we are at the stage to onboard developers to build on Harmony as we’ve already have the full span of infrastructure and toolings for Dapp building. We have integrated with Wallets such as Metamask, MathWallet, TrustWallet which have huge user base. We also have tooling support including web3.js, ethers.js, Truffle, Ganache, Graph Indexer etc. so Ethereum developers can feel at home when building solidity Dapps on Harmony.

We also have a healthy and strong community for Harmony with 250k+ supporters. Specifically, 200k+ on twitter, 27k+ on reddit, 25k+ on telegram and 10k+ on youtube.

499Block:That’s fascinating! Can’t wait to learn more about Harmony Project! Many users are more concerned about the application ecology of Harmony. Can you tell us what the application ecology of Harmony is like?

Rongjian Lan:Our application ecosystem has developed a lot throughout the past year and is getting bigger and bigger everyday. For Defi, we just launched SushiSwap on Harmony and have 70 millions dollars of TVL. We are the chain with the 3rd largest TVL in SushiSwap’s multi-chain system.

We also have many other Dexes such as ViperSwap, MochiSwap, AnySwap etc.

For stablecoins, we have binance BUSD and TerraUSD integrated. For NFT, we have our native NFT listing and trading platform called Davinci which have 2000+ creators and $500k+ sales so far.

This pic shows the bigger picture of the full Harmony ecosystem. And I think that’s the best way to show it .

499Block:Such a promising ecosystem, enormous diversity!

After knowing so much, I am very looking forward to the future of Harmony, How is the development route planning of Harmony?

Rongjian Lan:We are continuously working on multiple areas of the Harmony blockchain ecosystem.On the core protocol side, we are working on further improving the decentralization of the Harmony network by extending open validator slots up to 1000.

Resharding is also a key component of the system which we are working on, that includes fast state sync, validator state pruning etc.In addition, we are also working on a cross-shard smart contract feature which enables smart contract composability between shards.

On the Dapp ecosystem and tooling side, we are working on onboarding more Defi partners such as Aave, Bancor etc. to bring the full suite of Eth defi ecosystem to Harmony. We are also talking with Vietnam teams on bringing their GameFi applications to Harmony.

Besides, we are working on bridges to Bitcoin, Cosmos etc to further broaden our cross-chain bridging capabilities. Once the chains are bridged, we plan to provide a cross-chain API for developers to easily transfer and swap assets between chains.

499Block:Finally we have the last official question of the day. Is there any news that can be shared with us in the near future?

Rongjian Lan:We are currently hosting a world-wide Hackathon with a total of $1 million rewards. There are multiple tracks including “cross-chain with trustless bridges”, “social wallets and key-less security”, “cross-boarder with fin-tech integration”.

There will be judges from renowned organizations such as Coinbase, Sushi, Terra, UMA, Oasis and HashKey etc. There will be various panels with the above judges and many tutorial and office hour sessions for the developers.

We also provided many project templates for developers to quickly ramp up on building in Harmony

The hackathon just started yesterday and the registration is still open. We welcome all developers to participate in the hackathon, build on Harmony and win the generous prices. Register here:

499Block:Look forward to more updates of Harmony project in the future! Thanks to @RongjianLan for sharing!

Rongjian Lan:Thanks guys! Appreciate it! Thanks for hosting me for the AMA.